Mounting ring for vibrating screens



Aug. 26, 1969 I BE ET AL 3,463,315

MOUNTING RING FOR VIBRATING SCREENS Filed Dec. 13. 1967 5 Sheets-Sheet 1 IO\ 20 I (9 I31 W I 1. I52 l\\ i INVENTORS I60 I64 LAVERNE J. RIESBECK a WILLIS A. BLACKWELL ATTORNEYS Aug. 26, 1969 1.; J. RIESBECK fm. 3,463,315

. MOUNTING RING FOR vmnmmc scnsmus Filed Dec. 15. 1967 s Sheets-vSheet 2 I 1, k 49 FIG. 3

FIG. 4

5' INVENTORS LAVERNE J. RIESBEC I WILLIS A. BLACKWE Maw/ W ATTORNEYS Aug. 26, 1969 R|E5BEK ET AL 3,463,315

" MOUNTING RING FOR VIBRATING SCREENS Filed Dec. 13, 1967 5 Sheets-Sheet 5 g r.- 420, mai- 4 2 53b 33 33b INVENTQRS 7 LAVERNE J. mes CK a F [G 8 WILLIS A .BLAC ELL FIG. l0" WM M ATTORNEYS United States Patent Ofiice 3,463,315 Patented Aug. 26, 1969 MOUNTING RING FOR VIBRATING SCREENS Laverne J. Riesbeck and Willis A. Blackwell, Canton,

Ohio, assignors to Midwestern Equipment Co., Inc.,

Massillon, Ohio, a corporation of Ohio Filed Dec. 13, 1967, Ser. No. 690,318 Int. Cl. B07b 1/28 US. Cl. 209-323 16 Claims ABSTRACT OF THE DISCLOSURE An annular frame for mounting a vibrating screen in a material separator. The frame is made of a rigid thermoplastic material and has two recesses therein. A top recess is available for receiving a screen mounting apparatus when a frame in the material separator is used to mount a single screen. A bottom recess is available for receiving a second screen or plate making a single frame adaptable as a self-cleaning apparatus.

BACKGROUND OF THE INVENTION The invention consists generally of an annular frame for a vibrating screen for use in material separators or classifiers such as that disclosed in US. Patent No. 3,035,700.

Prior frames of which we are aware are fabricated of stainless steel having a rectangular or sequare cross section. Stainless steel is used to provide the frame with the necessary structural strength to support the screen when -loaded and vibrating during the material separation process. One form of ring now being used is a solid rectangular block to which a desired screen is welded. A top annular plate is then fastened over the welded portion of the screen to give the ring added strength and provide the screen with adequate protection from shearing or tearing. While providing an optimum of structural strength, being of stainless steel, these rings must be cast in one piece. This proves burdensome due to the fact that some of these rings are manufactured up to sixty inches in diameter. This fact alone, coupled with the fact that the rings must be precisionally constructed, makes each ring a costly item.

Being so constructed, these stainless frames often outlive the useful life of the screen attached thereto. When such is the case, rather than purchase another entire new frame and ring assembly, the industrialist usually sends the old frame with the wornout screen back to the manufacturer to be rescreened. This, of course, involves a complex and expensive accounting system due to the vast number of screens most users employ. Thus, the wornout frame-screen assembly must be listed, packed, and shipped for rescreening.

The rescreening process itself is also quite complex and burdensome. First the top cover plate or ring must be chipped off and the old screen removed and discarded; next the ring must be ground to a smooth surface for receiving a new screen and top ring; then the new screen and top ring must be carefully welded in place; and finally the revitalized ring must be sent back to the correct owner. Inherent again in this facet is a complex accounting system on the part of the rescreener.

The cost of each rescreening is usually well over onehalf the original cost of the frame and screen. Yet going through the rescreening process is more economically sound than purchasing an entire new apparatus every time a screen wears out. However, due to the fact that the stainless steel frame is subjected to grinding and another welding during each rescreening, its useful life is substantially shortened. Generally, after three or four rescreenings, the costly frame must be discarded.

In attempting to cut costs, ring manufacturers began making the aforementioned solid stainless steel rings hollow, hoping to be able to lower the original cost enough so that the stainless steel rings could be disposably used yet keeping the same level of sturdiness in the structure. However, most users still elected to rescreen their hollow rings due to continuing economic justifications.

Other attempts have been made to provide a disposable ring. One such attempt features a steel or stainless master frame which housed an inner steel ring, the master being reusable when the screen wears out However, this method has its deficiencies in that not being integrally made, the parts are rarely compatible; that is, it is diflicult to precisionally fit a new steel ring in the master. To do so requires many man-hours for each replacement. Further, if not properly tightened, the ring and frame assembly will rattle about causing unwanted friction on vital parts.

The rescreening problem is even more acute when the screens of a material separator are to be provided with self-cleaning features. These features are required in separators which are used to classify materials which tend to cling to or otherwise clog the screening. Prior self-cleaning devices consisted merely of placing two frame and screen assemblies rather close to each other in proximate horizontal planes. Rubber balls or some other obstruction were then placed between these screens. As the machine vibrated during the separating process, the bouncing action of these balls caused a cleaning action with respect to the screens. Note that at times, rather than use two screens in such an apparatus, the lower frame carried a perforated plate which served as a base for the vibrating obstructions.

While it is possible to weld another screen to the bottom of the present stainless steel rings, thus providing a selfeleaning apparatus by using only one ring instead of the customary dual ring requirement, when this system is employed, the additional heating and welding make the ring unsuitable for the above-described rescreening process. Thus it 1s not economically feasible to use a present stainless steel ring as a sole self-cleaning ring.

SUMMARY OF THE INVENTION It is thus an object of this invention to provide a ring which is suitable for self-cleaning adaptations without having to employ a second ring assembly.

It is another object of this invention to provide a ring of a rigid thermoplastic material constructed so as to meet the requisite strength requirements and so that it is economically feasible to dispose of it after one use.

Still another object of this invention is to provide a ring which can be manufactured in circumferential sections which not only achieve the desired durability features by being integrally bonded, but also reduce the cost of manufacturing the ring.

The invention, then, comprises an annular frame for mounting a screen in a material separator or classifier. The frame or ring can be made of a rigid thermoplastic material and is provided with two recesses. If the ring is to be used for mounting a single screen, then only one recess is supplied with a screen mounting apparatus. If the self-cleaning features are to be employed, another screen mounting apparatus can be provided for the second recess. Generally, a screen mounting apparatus consists of a screen welded between one leg of an angle member and an annular top ring. The other leg of the angle member fits in the recess of the mounting ring.

A further characteristic of this ring is that it can be manufactured in circumferential sections, yet due to a unique connection system, it retains the durability required for use in material separators.

The preferred embodiments of the present invention are shown by way of example in the accompanying drawings and hereinafter described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied; the invention being measured by the appended claims and not the details of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of a material separator having three of the mounting rings.

FIG. 2 is an enlarged, fragmentary sectional view taken substantially along line 2-2 of FIG. 1.

FIG. 3 is a view similar to FIG. 2 showing a ring utilizing the self-cleaning embodiment.

FIG. 4 is a partially sectioned fragmented plan view taken substantially along line 4-4 of FIG. 3.

FIG. 5 is a sectional view of another embodiment of the mounting ring with one screen attached.

FIG. 6 is a top view of two segments of the mounting ring of FIG. 2.

FIG. 7 is a side view of two segments of the mounting ring of FIG. 2.

FIG. 8 is a face view of one of the mating surfaces of a segment taken substantially along line 88 of FIG. 7.

FIG. 9 is a face view of the other mating surface of a segment taken substantially along line 9-9 of FIG. 7.

FIG. 10 is a view taken substantially along line 1010 of FIG. 7.

FIG. 11 is a partial sectional view of another embodiment of the mounting ring being shown as a self-cleaning apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, numeral 10 indicates a typical material separator having a cylindrical base 11 which supports, by means of a plurality of springs 12, a base plate 13. Extending downward and radially inward from plate 13 are a plurality of ribs 14 which combine with plate 13 to hold an electric motor 15 within cylindrical cavity 16 which is, in turn, within the confines of cylindrical base 11. Electric motor 15 has, at the top and bottom thereof, eccentric weights 17 which give the material separator 10 its vibrating motion.

Supported by base plate 13 are a series of axially adjacent cylindrical sections 18. A cover 19 is placed on the top section 18, cover 19 having an inlet 20 for the introduction of the material to be separated. Each section 18 also contains a chute 21 for the departure of the classified materials.

As best shown in FIGS. 2 and 3, each section 18 has a radially outwardly directed flange 22 at the axial end thereof. Intermediate the sections 18 is a mounting ring and screen assembly, shown generally as numeral 30. As will hereinafter more particularly be described, a U-shaped clamping ring 23 is constricted by draw bolts 24 (FIG. 1) to hold sections 18 at flanges 22 firmly together with ring and screen assembly 30 therebetween.

Referring particularly to FIG. 2, one form of mounting ring according to this invention is shown as numeral 31. Ring 31 is somewhat S-shaped in cross section having annular recesses 32 and 33 in the top and bottom thereof respectively. It can be made of any suitable rigid thermoplastic, polyvinyl chloride being a nonlimiting example thereof. The embodiment of FIG. 2 shows ring 31 mounting a single screen 34. Screen 34 is welded to one leg of an annular angle member 35, the other leg of which fits into recess 32.

A suitable bonding agent 36, such as epoxy cement, holds angle member 35 in juxtaposition with ring 31. Welded on top of screen 34 and angle member 35 is an annular steel top plate 37 which has, at the underside of its radially inward edge, a bevel 38. The radially inward vertical portion 40 of ring 31 has, at the top thereof, a bevel 39. When top plate 37 is placed on screen 34 and angle member 35, bevels 38 and 39 provide a V-shaped recess for the placement of a silicone protecting gasket 41 which prevents screen 34 from tearing or abrading along top plate 37 or vertical portion 40. Gasket 41 is generally applied in a semimolten state and allowed to cool and harden in place, thus forming good protection for screen 34.

Ring 31 terminates radially outwardly in a lip 42. Fitted around lip 42 is a rubber gasket 43 which is placed between flanges 22 of two adjacent sections 18. Entire ring and screen assembly 30 is held in place by the constriction of clamp ring 23 upon the tightening of draw bolts 24. Gasket 43 serves to protect the various components from undue friction and wear while the vibrator 10 is in operation.

FIG. 5 shows a variation in the components of the ring and screen assembly 30. In this embodiment, a plastic top ring 44 is shown having a bevelled edge 45. Top ring 44 is fastened to angle member 35 by a bonding agent 46. Again, epoxy cement serves as a good bonding agent. This embodiment is used most often in the relatively smaller diameter rings, such as the lS-inch design, where the metal top ring is not needed to add structural strength.

The ring and screen assembly 30 of FIG. 2 is shown in FIG. 3 with additional apparatus which demonstrate the adaptability of ring 31 as a self-cleaning assembly. In this embodiment one leg of a second angle member 47 is placed in bottom recess 33 and fastened thereto by bonding agent 48. Welded to the other leg of angle member 47 is a circular steel perforated plate 49. As will hereinafter be discussed, it is just as suitable to use another screen, similar to screen 34, in place of plate 49. An annular bottom plate 50 is welded to perforated plate 49 to give added strength to the structure.

Plate 49 is shown with a plurality of apertures 51 therein. The size of these apertures is not critical; however, it should be evident that they must be large enough to allow all of the material which has been selectively filtered through screen 34 to pass therethrough.

Plate 49 movably supports, as shown in FIG. 3, a plurality of plastic cylindrical obstructions 52. The size and shape of these obstructions are not of great significance. In fact, rubber balls serve just as well as the cylindrical obstructions 52 shown. As separator 10 vibrates, obstructions 52 will tend to bounce between plate 49 and screen 34, thus dislodging any material adhering to screen 34.

As alluded to above, a screen similar to screen 34 may be used in place of plate 49. It would be important, however, if such a second screen were used, that it be somewhat coarser and more durable than screen 34. Not only must this screen constantly support the weight and downward vibratory force of obstructions 52, but also all of the material selectively filtered through screen 34 must pass through the second screen. It is evident that if such a screen were of a finer nature, the material passing through screen 34 would not pass through the second screen. It should also be noted that if a second screen were used in place of plate 49, angle member 47 and bottom plate 50 would have to be beveled and a silicone protecting gasket, much like gasket 41 used for top screen 34, molded into the recess formed by the bevels. This would be quite critical due to the extra downward forces created by obstructions 52 which would tend to tear the second screen.

While it would be advisable to manufacture ring 31 as one molded piece in relatively smaller diameter rings, for the larger diameter rings, it is advantageous to mold ring 31 in circumferential sections and then fasten them together. It has been found that for best results, five sections are preferred for each ring.

FIG. 6-10 show two such sections 31a and 31b. Because durability of the rings is critical, the connection of these sections becomes of great importance. Sections 31a and 31b each have connecting flanges 53a and 53b, respectively, which interlock with receiving cavities 54b and 54a, respectively. To assure a permanent bond between each section, all mating surfaces are first covered with an epoxy resin material. Then the epoxy covered flanges are interlocked, that is, flange 53a fits snugly into cavity 54b, and flange 53b fits snugly into cavity 54a. While it is felt that such a bonded structure would achieve the desired durability, complete bonding can be further achieved by heating the mating area of each section so that a fusion of the thermoplastic material takes place. Thus a permanent bond is assured.

FIG. 11 shows another embodiment of this invention, generally to be used in the smaller diameter rings where non-section molding is advantageous. Here, annular mounting ring 131 is somewhat U-shaped in cross section having a radially outward annular lip 142 for connection to the material separator.

Ring 131 is again preferably made of a rigid thermoplastic material such as polyvinyl chloride. Screen 134 is fastened to ring 131 by an epoxy resin and further held securely in place by annular top plate 137. Top plate 137 has, at the underside of its radially inward edge, a bevel 138 which provides a recess for the placement of a silicone protecting gasket 141, which is generally applied in a semimolten state and allowed to cool and harden in place, thus preventing screen 134 from tearing or abrading on the edge of plate 137 or ring 131.

If ring 131 is to be used as a self-cleaning device, then an annular metallic insert 160 having a rectangular cross section is placed in the U-shaped channel formed by ring 131. Insert 160 is fastened to ring 131 by a bonding agent 161. Note that it is not necessary to make insert 160 out of any particularly high grade metal such as stainless steel, because it need not have any specific durability or anticorrosive features. Thus, the insert 160 does not add appreciably to the cost of the ring assembly.

Welded to insert 160 is a second screen 162. An annular bottom plate 150 is welded to screen 162 and insert 160 to give added strength to the structure. Bottom plate 150 has, at the upper edge of is radially inward point, a bevel 163 which forms a recess for the placement of a silicone protecting gasket 164 which is generally applied in a semimolten state and allowed to cool and harden in place thus preventing screen 162 from tearing or abrading on the edge of plate 150 or ring 131.

In this embodiment, rubber balls 152 are shown as the obstruction which tends to dislodge any material wedged in screen 134, performing much like the cylindrical obstrutions 52 in FIG. 3. Note also that a circular perforated steel plate such as the plate 49 shown in FIG. 3 may also be used in the FIG. 11 embodiment. Of course, bevel 163 and gasket 164 would not then be necessary.

It can be seen that a mounting ring made under the above specifications will not only provide an inexpensive, sturdy, and disposable construction, but also will allow one to use a single frame for the self-cleaning arrangement, thus carrying out the aforementioned objectives and substantially improving the mounting ring art.

We claim:

1. A vibrating screen frame for use in a material separator comprising a rigid annular plastic ring having a vertically directed annular recess therein for receiving a vertically directed annular leg of a sceen mounting assembly.

2. A frame according to claim 1, wherein said plastic ring has a radially outer annular lip for mounting in the material separator.

3. A frame according to claim 1, wherein said plastic material is polyvinyl chloride.

4. A frame according to claim 1, wherein said screen mounting assembly comprises a screen overlapping and fastened to one leg of an annular angle member, the other leg being received and fastened in said recess.

5. A frame according to claim 4, wherein an annular plate is fastened over said screen and said one leg of said annular angle member.

6. A frame according to claim 5, wherein the top of the radially inner portion of said ring is beveled downwardly inward and the underside of the radially inner portion of said annular plate is beveled upwardly inward forming a V-shaped recess with the beveled portion of said ring for receiving an annular silicone protecting gasket to prevent said screen from tearing on said annular plate.

7. A vibrating screen frame for use in a material separator comprising an annular plastic ring having an annular recess in the top thereof for receiving an annular leg of a screen mounting assembly and said ring having a second annular recess in the bottom thereof for receiving an annular leg of a second screen mounting assembly.

8. A frame according to claim 7, wherein said ring is formed of a plurality of circumferential sections, each section being bonded to the adjacent section by connecting means, said plurality of sections forming the entire annular ring.

9. A frame according to claim 7, wherein said first screen mounting assembly consists of a first screen overlapping and fastened to one leg of a first annular angle member, the other leg of said first angle member being received and fastened in said first recess, and said second screen mounting assembly consists of a second screen overlapping and fastened to one leg of a second annular angle member, the other leg of said second angle member being received and fastened in said second recess.

10. A frame according to claim 9, wherein a plurality of obstructions are movably supported between said first screen and said second screen, said obstructions vibrating during the operation of the material separator to loosen any material lodged in said screens.

11. A frame according to claim 7, wherein said first screen mounting assembly consists of a screen overlapping and fastened to one leg of a first annular angle member, the other leg of said first angle member being received and fastened in said first recess, and said second screen mounting assembly consists of a perforated plate overlapping and fastened to one leg of a second annular angle member, the other leg of said second angle member being received and fastened in said second recess.

12. A frame according to claim 11, wherein a plurality of obstructions are movably supported between said screen and said perforated plate, said obstructions vibrating during the operation of the material separator to loosen any material lodged in said screen.

13. A frame according to claim 12, wherein said obstructions consist of plastic cylinders.

14. A vibrating screen frame for use in a material separator comprising, an annular plastic ring having a U-shaped channel therein, a radially outer annular lip for mounting in the material separator, a first screen fastened to the top of said ring, and a plastic annular plate fastened on said screen and said ring.

15. A frame according to claim 14, wherein a metallic annular insert is mounted in said U-shaped channel, a second screen is fastened to said insert, and an annular metallic plate is fastened on said screen and said insert.

16. A material separator, comprising (a) a series of axially adjacent cylindrical sections, each having radially outwardly directed flanges at their adjacent ends;

(b) a series of frames each comprising an annular plastic ring having a first recess in the top thereof and a second recess in the bottom thereof for receiving screen mounting assemblies, and a radially outer annular lip on said plastic ring;

(0) a series of gasket rings fitted over the peripheries of said annular lips, said gasket rings fitting between said radially outwardly directed flanges of said cylindrical sections; and

(d) a constrictable clamp ring fitted over each axially 7 8 adjacent pair of said radially outwardly directed 3,167,004 1/1965 Miller et a1. 101-415.1X flanges to hold each said frame between each pair 3,169,475 2/1965 CaQuette 209-408 X of said outwardly directed flanges. 3,243,042 3/1966 Moulton 209408 X 3,341,013 9/1967 Moulton 209405X References Clted 5 3,352,418 11/1967 Swallow 209-403 UNITED STATES PATENTS 1,073,325 9/1913 Spring 209-399); FOREIGN PATENTS 2,197,435 4/1940 Niemeyer 209-403 2,271,900 2/1942 Mowbray 209 403 10 1641916 12/1949 Amma- 2,670,079 2/1954 136m 209 4o5 2,677,462 5/1954 Conkling 209 405 X TIM MILES Primary Exam! 2,903,967 9/1959 Levin. 3,029,946 4/1962 Wright et a1 209-405 3,035,700 5/1962 McCausland 209-405 3,042,206 7/1962 Olender 209-40554 

